


Kingdom Come

by rehliamonster



Category: Undertale (Video Game)
Genre: Broken Friendship, Cuckolding, Exhibitionism, F/M, M/M, Masturbation, One-Sided Attraction, Sad Porn, Self Confidence Issues, Size Kink, Unrequited Crush, Voyeurism, implied prostitution
Language: English
Status: Completed
Published: 2017-02-16
Updated: 2017-02-16
Packaged: 2018-09-25 00:19:45
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,472
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9794069
Author URL: https://archiveofourown.org/users/rehliamonster/pseuds/rehliamonster
Summary: Alphys has finished building Mettaton's body and now it's time for a demonstration in front of the King, to prove that she's worthy of the position of the Royal Scientist.It's everything she's ever wanted and everything she hates.





	

“W-what?” 

Asgore’s deep voice is a mixture of confusion, shock and concern. 

Oh no. 

Oh no, she messed it up, didn't she? Of course there's no way that this information she got about him was right, she's so dumb to believe it, stupid stupid stupid -

“I am equipped to entertain monsters in many possible ways,” Mettaton says smoothly. He's so good at making the statement sound both innocent and lewd at once. Alphys has no idea how he does that, she wishes she was that good at double entendres.

The King watches with wide eyes as Mettaton shifts from the boxy form he came here as into the more human one that she hasn't quite finished yet. The batteries just don't last all that long, she needs to work on that… it should be enough for a demonstration though. Hopefully. Oh, what will she do if they don't last long enough? 

Alphys feels sweat gathering under her armpits and on her forehead and the sticky feeling makes her feel disgusted with herself. 

She should be better than this! Mettaton is doing so much to help her - and she's doing this to help him as well, okay, but she can't blow this for him or herself -

Mettaton is now leaning forwards, one hand placed on the massive furry paw of his King.

“I intend to create television shows for them to watch and enjoy, fan events, live shows in a special resort venue… and to give them companionship where they need it,” he purrs. His fingers are sliding through the fur on Asgore’s paw. 

The King looks almost helpless on his throne, his handsome face mesmerised and awestruck at the robot standing in front of him. He's obviously already impressed by what he's seen so far, oh stars, yes, she hoped so much he would be, she wants this so badly, but will it be enough?

“That sounds wonderful,” Asgore finally says, the to deep tenor of his voice quiet and soft. 

“Doesn't it?” Mettaton's voice is positively dripping with sensuality. 

Alphys catches the way Asgore’s eyes roam over Mettaton's metallic body, the sleek and polished panels, the small gaps where wires are exposed, the sturdy glass casing housing a delicate soul for everyone to see.

Daring. 

Revealing. 

She wants to hide her face at the sight just as she did when he first told her that this was the design he wanted, but she has to stay professional in front of the King and she also has a really hard time looking away for _some reason_ , and so she just ends up twisting her fingers into the fabric of her lab coat, bunching up the material between her clammy fingers until it stays wrinkled. 

Oh no. She especially had it cleaned and pressed for today. 

She's such a mess!

In front of her Asgore has managed to wrestle his eyes away from Mettaton, staring off to the side, away from both the robot and her.

“I am sure you will make many monsters very happy,” Asgore says. 

Alphys hates how he sounds in that moment, sad and defeated. 

He shouldn't sound like that. He's so good looking and working so hard for everyone in the Underground and so kind and strong and big and muscular -

She takes a big breath. 

He should be happy, that's what she means. He tries to make everyone in the kingdom happy but he should get to be happy too. 

_The King is lonely_ , it had been whispered to her when she had found the monster she had been told could help her, who would know what might impress the ruler of the Underground enough to make her his royal scientist. _The King is sad and lonely but he's passive and meek in these things and he'd never initiate. The key to the King is soothing that sadness, that loneliness._

Mettaton had been receptive to the idea. Very receptive, actually, since he'd be getting something out of it too. He's leaning closer to Asgore now, just a little bit too close for it to still be counted as innocent.

It's so risky and _daring_ , jeez, she can't watch, but she also can't stop watching. 

“That is what I was build for,” Mettaton says, tilting Asgore’s head back so they're facing each other again. “I was built to make monsters happy. Starting with you…”

Asgore’s eyes widen when Mettaton leans forwards and presses his lips against the furry tip of Asgore’s snout, before dipping lower and running his tongue across the King's mouth. 

Alphys holds her breath, too much, too far, Mettaton is too fast and the king will be insulted and they'll be thrown out - or worse, locked into a _dungeon_ , she has never heard of there actually being dungeons but surely they must exist and she'll be left to rot there -

Oh.

Oh, Asgore has actually opened his mouth. 

And Mettaton is French kissing him now. 

Okay. 

_Her best friend is French kissing her crush._

She doesn't even know if she feels jealous or turned on, a little bit of both probably, and she's still just… standing here and watching and clenching her hands against her lab coat.

Should she leave? Mettaton is beginning to clambers onto Asgore’s lap and she thinks maybe she should leave, but her eyes are glued to the proceedings in front of her. 

Mettaton moves and Asgore only responds, never initiates, passive and meek as described. 

When she had imagined - well, not _this_ certainly, no, in her dreams there had been no Mettaton present, only her and the handsome burly King, but when she had imagined Asgore during sex, she had always imagined him as more confident and forceful, an image to fit with the powerful muscles rippling under his pristine white fur. 

And now she might get to see it for _real_ , see what it's actually _like_ when Asgore has sex… 

Not with her, but with her best friend. 

She should probably leave.

She doesn’t. 

Mettaton opens the strings of Asgore’s breeches, pulling the length free that has steadily grown bigger under the fabric, a truly impressive shaft.

It was even bigger than she had imagined. 

Mettaton guides it carefully to the entrance he had her design for him, a part of his anatomy that she'd had great trouble working on but also a lot of fun because it was so _lewd_ but designing something mechanical to be as fleshlike as possible was also _interesting_ -

Asgore’s massive dick penetrates Mettaton and the monster it belongs to moans, deep and low and reverberating.

It's such a nice sound. 

Alphys finds her clenching hands wandering and sharply draws back, no, no no no she can't do that, oh stars no. 

Asgore moans again as Mettaton sinks down, the very wide opening he had her design for his body barely enough to take the King's spectacular size. She keeps staring at how the soft folds of Mettaton's opening wrap around the flesh, glistening with lubrication. When she does glance up, Asgore’s eyes are closed, his expression blissful. 

_That_ had been something she had figured out all by herself! It was rather obvious that there were very, very few monsters big enough to take the King in his entirety. But Mettaton had wanted for his body to be big and to have that part of him be flexible anyway, and so she had made it big enough - well barely - for the King. 

She just - she never expected this to actually happen -

Mettaton has started moaning too which is weird, and there are wet slapping sound echoing through the throne room with each of his movements on Asgore’s lap. 

She bites her lower lip and fiddles with a button of her lab coat. 

So lewd…

Oh no, her hand has slipped under her lab coat. 

Stars, she’s the worst, her best friend is fucking the King and she’s - 

She’s touching herself to it.

Her teeth dig harder into her lower lip as she begins to circle her fingers around her own opening, brushing against her clit every so often. She doesn’t want to make a noise, this is terrible enough as it is, really. She’s awkwardly holding the clipboard she brought with her in front of her groin, not that it does much to hide where her hand has strayed and what she’s doing, but it makes her feel better anyway. 

Mettaton speeds up his movements, his moans getting higher in pitch while Asgore’s grow deeper, both getting louder. 

Alphys suppresses her own squeak at the sights and the sounds, the confused arousal that courses through her body. She’s very wet and it’s, yeah, she can admit this, it’s pretty hot to be watching this, but it also disturbs her because it’s still her best friend and her crush and this is _weird_ but she’s getting off to it anyway. 

Another brush against her clit and she accidentally lets out a small moan of her own, the intense pleasure automatically transforming into sound. It’s fine though, it’s not very audible underneath the noise Asgore and Mettaton make.

This isn’t enough. 

She carefully reaches lower and inserts a finger into her pussy, having trouble with the angle thanks to her standing up and being a little tense and trying to hide behind that stupid clipboard, but it feels so good and so satisfying. 

She speeds up her motions to match the pacing Mettaton sets on Asgore’s cock and imagines that it’s her fucking the king, that she’s the one riding that massive length, spearing herself on it repeatedly while the handsome face of her crush contorts itself into the beautiful agony of lust. 

It would probably feel so good inside her, that big head rubbing against her walls and bottoming out deep in her pussy… it would never fit, it would never work, but she doesn’t think about that now, only watches the cock of the man she desires vanish into the wide cunt of her best friend, imagining it could work, that it’s her. 

Her breath stutters when she thinks of Asgore’s hands wrapping around her hips, moving her up and down as if she was only a toy for him to use, just something he pleasures himself with ruthlessly. 

It’s one of her favourite fantasies and even now when confronted with the fact that it doesn’t match reality she still likes to imagine it.

Or maybe… maybe he could wrap those hands around her and look down at her with gentle adoration and love, and they’d move together, oh yeah, yeah, she likes that, his expression right now is so soft and open and vulnerable and maybe they could be soft and open and vulnerable together and she could feel small and safe in his arms but he could also feel like he didn’t have to be strong and protect her even though she would like that, because she’d be his royal scientist and he’d tell her how clever and good and lovely she is - 

Alphys plunges her fingers into herself furiously, her own aborted squeaks and gasps joining the raw moans of the two men in front of her. She’s the first to come, a high pitched squeal leaving her that she immediately tries to choke back, but they aren’t reacting to it. Her orgasm is a blistering heat of releasing tension and burning desire and intense jealousy, a confusing mix that leaves her unsteady on her feet. She withdraws her hand from herself and self-consciously wipes her hand down on her lab coat before closing the button she opened again. 

She’s still sweating, but forces her breath to calm down as she watches Mettaton climax on Asgore’s cock, clenching so hard around him that the King immediately follows, a perfect near-simultaneous orgasm that she’s so far only seen in movies. 

Not that she’s seen many orgasms in the first place. 

Their last, long moans are followed by a deep silence as they lean their heads on the other’s shoulder. She can see Asgore’s face, exhausted and blissed out, for once utterly relaxed and carefree. 

Alphys supposes that this is worth the lump in her throat and the disgust she feels at herself. And maybe also at Mettaton. She can’t see his face at all. 

They slowly untangle themselves from each other, the latch on Mettaton’s lower half sliding shut to hide his genitals once more, while he helps the King straighten out his breeches in silence. 

Mettaton gives Asgore a last quick kiss on his cheek and then walks back to Alphys, standing next to her as if nothing of importance happened, looking as innocent as a robotic body created to ooze sex appeal can look. 

Alphys gulps and tries to straighten her posture when Asgore’s attention shifts back to her. 

Oh no. Will he scold her now? Praise her? Hire her? Throw her into a dungeon after all? 

Did he notice that she had been here the entire time? Did he notice what she’d _done_?

“I have your address,” the King finally proclaims in a quiet voice. “I will send guards to help you move into the lab tomorrow.”

She blinks at him and it takes her a second before she’s able to process what he just said, she’s hired, she’s _hired_ , she’s the _royal scientist now, one of the most prestigious positions in the Underground is all hers._

She’ll be working directly under Asgore. 

Her crush. 

The man who just fucked her best friend. 

“Th-thank you, your majesty - I! I mean. I mean, A… A-asgore…”

“You are quite welcome. I look forward to what you and your creation will bring to the Underground.”

He waves his paw in a manner that tells her they’re dismissed and they leave quietly through the door, walking down the hall in silence. Mettaton stops somewhere along the way to revert back to his boxy form to save energy. 

“So. We did it! Congratulations,” Mettaton tells her, his voice slightly smug. 

Of course he is. He just fucked the King. 

He helped her, she firmly tells herself, he did it to help her, they did this together, she asked him to, she hates him a little bit and she’s disgusting and she’s the _worst_.

“Y-yeah. Congrats to you too.”

He must be able to tell she’s not as happy as she should be, since he doesn’t say anything else on the way back, only telling her goodbye when it’s time to go home. 

She moves into the lab on the next day and she doesn’t hear from Mettaton, but that’s okay since she’s not really contacting him either. It becomes a thing over the years. He becomes a star and she becomes a mess and she always wonders if that’s her punishment for being so terrible about what happened. 

They never quite recover from it.


End file.
